WO2019230871A1

WO2019230871A1 - Composite material and bioimplant

Info

Publication number: WO2019230871A1
Application number: PCT/JP2019/021484
Authority: WO
Inventors: 健一雑賀; 渡辺　健一; 京本　政之
Original assignee: 京セラ株式会社
Priority date: 2018-06-01
Filing date: 2019-05-30
Publication date: 2019-12-05
Also published as: JP7155259B2; EP3804768A1; CN112188903A; AU2019279208A1; AU2019279208B2; JP2023015032A; JP2024028859A; EP3804768A4; JP7400049B2; US20210196862A1; JPWO2019230871A1; EP3804768A9

Abstract

A composite material according to one embodiment has a crystal phase of a titanium fluoride and a metal crystal phase of titanium. The crystal phase of titanium fluoride is present in a first region located away from the surface in the depth direction.

Description

Composite materials and bioimplants

The present disclosure relates to composite materials and biological implants.

Metal materials in which fluorine ions are implanted on the surface are known (see, for example, Patent Document 1 and Non-Patent Document 1).

Japanese Patent No. 4568396

The composite material according to one embodiment has a crystal phase of titanium fluoride and a metal crystal phase of titanium. The crystalline phase of titanium fluoride exists in the first region located away from the surface in the depth direction.

A biological implant according to an embodiment includes the composite material according to the embodiment.

FIG. 1 is a schematic view showing a composite material according to an embodiment. FIG. 2 is an example of a biological implant according to an embodiment. FIG. 3 is a graph showing measurement results of fluorine concentration in the examples. FIG. 4 is a graph showing the measurement results of hardness in Examples and Comparative Examples.

<Composite material>
Hereinafter, a composite material according to an embodiment will be described in detail with reference to the drawings. However, for convenience of explanation, the drawings referred to below show only a configuration necessary for describing the embodiment in a simplified manner. Thus, a composite material according to one embodiment may have any configuration not shown in the referenced figures. In addition, the dimensions of the configuration in the drawing do not faithfully represent the dimensions and size ratio of the actual configuration. These points are the same in the biological implant described later.

FIG. 1 is a schematic view showing a composite material according to an embodiment. In FIG. 1, the cross section of the part containing the surface of a composite material is expanded and shown.

The composite material 1 contains titanium (Ti) and fluorine (F), and includes a titanium fluoride crystal phase 2 (hereinafter sometimes referred to as “crystal phase 2”) and a titanium metal crystal phase 3 (hereinafter referred to as “crystal phase 2”). It may be referred to as “metal crystal phase 3”). In the crystal phase 2, titanium fluoride which is a compound of titanium and fluorine exists in a crystalline state. In the metal crystal phase 3, titanium exists in a crystal state constituted by metal bonds.

Since the composite material 1 contains fluorine and has the crystal phase 2 as described above, it is possible to exhibit antibacterial properties due to fluorine. Moreover, since the composite material 1 has a large hardness, it is possible to exhibit excellent wear resistance and the like. The reason why the composite material 1 has a large hardness is estimated as follows.

The bond between titanium and fluorine in titanium fluoride is a covalent bond. Therefore, the crystal phase 2 functions as an obstacle to transition that moves through the metal crystal phase 3. Therefore, when the composite material 1 has the crystal phase 2, the amount of energy required for the movement of transition increases, and as a result, the hardness of the composite material 1 increases. Note that as the fluorine concentration in the composite material 1 increases, the proportion of the crystal phase 2 tends to increase.

Examples of the titanium fluoride include TiF (titanium fluoride), TiF ₂ (titanium difluoride), TiF ₃ (titanium trifluoride), TiF ₄ (titanium tetrafluoride), TiOF (titanium oxyfluoride), and TiOF _2. (Titanium oxydifluoride) or F-TiO ₂ (fluorine-doped titanium oxide). Titanium fluoride may be a TiOF _2. The crystal phase 2 may have a Ti—F—Ti bond (covalent bond).

Examples of methods for measuring the crystal structure include a transmission electron microscope (hereinafter sometimes referred to as “TEM”) and X-ray diffraction (hereinafter referred to as “XRD”). ) Or X-ray photoelectron spectroscopy (X-ray Photoelectron Spectroscopy: hereinafter referred to as “XPS”).

The composite material 1 may include a region (first region) 12 including the surface 11 of the composite material 1 and having a predetermined thickness in the depth direction from the surface 11. The first region 12 is a composite phase of titanium and fluorine. The fluorine concentration in the first region 12 may be 1 ppm or more.

The thickness T of the first region 12 is, for example, 30 to 800 nm. In addition, when a numerical range is indicated using “to”, unless otherwise specified, the lower limit and the upper limit are included. For example, when the numerical range is 30 to 800 nm, the lower limit is 30 nm or more and the upper limit is 800 nm or less.

The crystal phase 2 may be located in the first region 12. When satisfying such a configuration, since the crystal phase 2 is located near the surface 11, the antibacterial property due to the fluorine of the titanium fluoride is enhanced, and the hardness of the surface 11 and the vicinity thereof can be increased.

The crystal phase 2 may be located in a region having a depth of 20 to 200 nm from the surface 11. The depth may be determined based on the surface 11.

The metal crystal phase 3 may have a first phase 31 (fluorine-containing phase) containing fluorine. In other words, the metal crystal phase 3 may have the first phase 31 containing fluorine in the crystal lattice of titanium. In the first phase 31, fluorine may be introduced as an interstitial element in the crystal lattice of titanium. If the metal crystal phase 3 has the first phase 31, the hardness of the composite material 1 can be further increased. The reason for this is presumed as follows.

In the first phase 31, fluorine atoms enter the space in the titanium crystal lattice constituted by metal bonds. Thereby, lattice distortion corresponding to the size of the invading fluorine atom occurs in the titanium crystal. The deformation of the crystal lattice of titanium is caused by the movement of transition, which is a defect of the crystal lattice. If the crystal lattice of titanium is distorted by the intrusion of fluorine atoms, the mobility of transition decreases, and as a result, the hardness of the composite material 1 increases. Therefore, if the metal crystal phase 3 has the first phase 31, the first phase 31 contributes to the hardness of the composite material 1 in addition to the crystal phase 2, so that the hardness of the composite material 1 is increased. Can do. Moreover, when the fluorine concentration in the composite material 1 is decreased, the proportion of the first phase 31 tends to increase.

The first phase 31 may be located in the first region 12. When satisfying such a configuration, since the first phase 31 is located near the surface 11, the hardness of the surface 11 and the vicinity thereof can be increased. The first region 12 where the first phase 31 is located is the same as the first region 12 where the crystal phase 2 is located. This also applies to the first region 12 where the second phase 32 described later is located, the first region 12 where the maximum value of fluorine concentration is located, and the first region 12 where the maximum value of hardness is located. That is, the first regions 12 in the description of each configuration are all the same.

The metal crystal phase 3 may further have a second phase 32 (fluorine-free phase) that does not contain fluorine and is located inward of the first phase 31. When satisfying such a configuration, the portion including the first phase 31 located closer to the surface 11 than the second phase 32 is less likely to be damaged. Specifically, the second phase 32 has higher toughness than the first phase 31 due to the fact that it does not contain fluorine. Therefore, when an impact is applied to the surface 11, the impact can be mitigated by the second phase 32 having relatively high toughness. As a result, the portion including the first phase 31 located on the surface 11 side with respect to the second phase 32 is less likely to be damaged.

It should be noted that the second phase 32 being located inward of the first phase 31 means that the second phase 32 is located farther from the surface 11 than the first phase 31. Inward means inside the composite material 1 with respect to the surface 11. In other words, inward means the direction in which the depth increases in the composite material 1. Further, the phrase “not containing fluorine” means a state that does not substantially contain fluorine and is not substantially affected by fluorine. Specifically, when the fluorine concentration is less than 1 ppm, it may be determined that no fluorine is contained.

The second phase 32 may be located inward of the first region 12. When satisfying such a configuration, the second region 32 having relatively high toughness makes it difficult for the first region 12 located closer to the surface 11 than the second phase 32 to be damaged.

The composite material 1 may further include a region (second region) 13 located inward of the first region 12. The second region may be a region containing titanium and not containing fluorine. The second phase 32 may be located in the second region. The second region 13 may be in contact with the first region 12. That is, the first region 12 and the second region 13 may be continuous regions in the composite material 1.

The metal crystal phase 3 may contain, for example, a titanium-based metal. Examples of the titanium-based metal include pure titanium or a titanium alloy. Pure titanium includes, for example, C.I. P. Examples include industrial pure titanium such as two types of titanium. The titanium alloy is an alloy whose parent phase is titanium. For example, Ti-6Al (aluminum) -4V (vanadium), Ti-15Mo (molybdenum) -5Zr (zirconium) -3Al, Ti-Nb (niobium), Ti -6Al-7Nb, Ti-6Al-2Nb-1Ta (tantalum), Ti-30Zr-Mo, Ni (nickel) -Ti, Ti-3Al-2.5V, Ti-10V-2Fe (iron) -3Al or Ti- And 15V-3Cr (chromium) -3Al-3Sn (tin).

The composite material 1 may further have an amorphous phase 4 (amorphous phase) containing titanium and fluorine. When satisfying such a configuration, the composite material 1 is hardly damaged by the high toughness of the amorphous phase 4.

The amorphous phase 4 may be located in the first region 12. When satisfying such a configuration, the first region 12 is hardly damaged by the high toughness of the amorphous phase 4.

The composite material 1 may further have a mixed phase 5 containing an amorphous phase 4, a crystal phase 2, and a metal crystal phase 3 (first phase 31). In one embodiment, the mixed phase 5 is located in the first region 12. In the mixed phase 5, a plurality of amorphous phases 4, crystal phases 2, and metal crystal phases 3 are mixed. In this case, although the material characteristics of each phase are different, the material characteristics of the composite material 1 in the first region 12 are characteristics corresponding to the proportion of each phase. Specifically, it becomes the characteristic which averaged the material characteristic of each phase to contain, or the characteristic close | similar to this. That is, the composite material 1 can reduce portions having different material properties in the first region by containing each phase as the mixed phase 5. Therefore, the composite material 1 having the mixed phase 5 can reduce the possibility that the material partially peels from the first region 12. That is, the stability of the composite material 1 can be improved.

In the composite material 1, the fluorine concentration may be a maximum value inward of the surface 11 (see FIG. 3). When satisfying such a configuration, when the new surface 11 is exposed due to wear or the like, the surface 11 having a relatively large fluorine concentration is likely to be exposed, so that antibacterial properties are easily exhibited over a long period of time.

The fluorine concentration may increase from the surface 11 inward and reach a maximum value (see FIG. 3). In other words, as the depth increases, the fluorine concentration may increase and reach a maximum value. When satisfying such a configuration, when the new surface 11 is exposed due to wear or the like, the surface 11 having a relatively large fluorine concentration is exposed, so that antibacterial properties can be exhibited over a long period of time. Moreover, the composite material 1 can adjust the time which exhibits antibacterial performance by adjusting distribution of fluorine concentration.

The maximum value of the fluorine concentration may be located in the first region 12. When satisfying such a configuration, the maximum value of the fluorine concentration is located near the surface 11, so that antibacterial properties are enhanced.

The maximum value of the fluorine concentration may be located closer to the surface 11 than the central portion 12a in the thickness direction A of the first region 12 (see FIGS. 1 and 3). When satisfying such a configuration, the maximum value of the fluorine concentration is located near the surface 11, so that antibacterial properties are enhanced.

Here, the concentration in fluorine concentration is atomic concentration. In one embodiment, the fluorine concentration is the number of fluorine atoms per unit volume relative to the sum of the ideal number of titanium atoms per unit volume and the number of fluorine atoms. Examples of the method for measuring the fluorine concentration include secondary ion mass spectrometry (Secondary / Ion / Mass / Spectrometry: hereinafter sometimes referred to as “SIMS”), XPS, and the like. SIMS is suitable when the fluorine concentration is relatively small. XPS is suitable when the fluorine concentration is relatively large.

The maximum value of the fluorine concentration is, for example, 10 to 80 atomic%. The fluorine concentration in the region less than 5 nm deep from the surface 11 is, for example, 0.5 to 20 atomic%. The fluorine concentration in the region having a depth of 5 nm or more and less than 20 nm is, for example, 2 to 30 atomic%. The fluorine concentration in the region having a depth of 20 nm or more and less than 50 nm is, for example, 5 to 80 atomic%. The fluorine concentration in the region having a depth of 50 nm or more and 100 nm or less is, for example, 2 to 80 atomic%.

The hardness of the composite material 1 may be a maximum value inward of the surface 11 (see FIG. 4). When such a configuration is satisfied, when the new surface 11 is exposed due to wear or the like, the surface 11 having a relatively large hardness is likely to be exposed, and thus the possibility that the surface 11 has a large hardness over a long period of time increases. . The surface 11 in the description of hardness is the same as the surface 11 in the description of fluorine concentration described above.

The hardness may increase from the surface 11 inward and reach a maximum value (see FIG. 4). In other words, as the depth increases, the hardness may increase and reach a maximum value. When satisfying such a configuration, when the new surface 11 is exposed due to wear or the like, the surface 11 having a relatively large hardness is exposed, so that the surface 11 has a large hardness over a long period of time.

Further, the hardness may increase as it goes inward from the surface 11 and reaches a maximum value, and then may decrease as it goes further inward (see FIG. 4). In other words, the composite material 1 may be configured such that the change in hardness is moderate inside. According to this, since the generation of local stress can be reduced as compared with a configuration in which the hardness inside the composite material 1 changes abruptly, the possibility that the first region 12 peels can be reduced. it can.

The maximum value of hardness may be located in the first region 12. When satisfying such a configuration, since the maximum hardness value is located near the surface 11, the hardness of the surface 11 and the vicinity thereof can be increased.

The maximum value of hardness may be located closer to the surface 11 than the central portion 12a in the thickness direction A of the first region 12 (see FIGS. 1 and 4). When satisfying such a configuration, since the maximum hardness value is located near the surface 11, the hardness of the surface 11 and the vicinity thereof can be increased.

The maximum value of hardness may be located closer to the surface 11 than the maximum value of fluorine concentration (see FIGS. 3 and 4). When such a configuration is satisfied, the hardness of the portion located near the surface 11 is relatively larger than the maximum value of the fluorine concentration. Therefore, the part located closer to the surface 11 than the maximum value of the fluorine concentration is less likely to be damaged by abrasion or the like, and can exhibit antibacterial properties over a long period of time.

The hardness is, for example, 3 to 10 GPa. The maximum value of hardness is, for example, 5 to 10 GPa. The hardness is indentation hardness and indicates the difficulty of deformation when the surface 11 is deformed. The hardness is calculated from the indentation depth when the indenter is pushed into the surface 11 and the required force. Specific examples of the hardness measurement method include a nanoindentation method (ISO 14577 compliant).

The composite material 1 may further include an oxide film (not shown) located on the outermost surface. In this case, the surface 11 of the composite material 1 consists of the surface of an oxide film. The thickness of the oxide film is, for example, 2 to 5 nm. Examples of the composition of the oxide film include TiO ₂ (titanium dioxide). The oxide film may contain fluorine. The oxide film is formed by, for example, oxidation treatment. Examples of the oxidation treatment include natural oxidation, heat treatment, oxygen plasma treatment, immersion in an acid solution, or anodic oxidation.

In the composite material 1, the titanium content may be greater than the fluorine content. The composite material 1 may contain titanium as a main component. The main component is a component that is most contained in the composite material 1 by mass ratio.

<Production method of composite material>
Next, the manufacturing method of the composite material according to the embodiment will be described in detail by taking as an example the case of obtaining the composite material 1 described above.

First, prepare a titanium-based metal. You may wash | clean a titanium-type metal as needed. For example, an organic solvent may be used for cleaning. Examples of the organic solvent include ethanol or acetone. The exemplified organic solvents may be used as a mixture. The cleaning may be performed by applying ultrasonic waves. The titanium-based metal after cleaning may be vacuum-dried in a desiccator, for example.

Next, fluorine ions are implanted into the surface of the titanium-based metal to obtain the composite material 1. Examples of fluorine ion implantation conditions include the following conditions.
Implant energy: greater than 30 keV and less than 80 keV Implant dose: 1 × 10 ¹⁶ to 5 × 10 ¹⁷ atoms / cm ² (atom / cm ² )

The obtained composite material 1 may be washed as necessary. The conditions for cleaning include the same conditions as exemplified for the titanium-based metal described above. The composite material 1 after washing may be vacuum-dried in a desiccator, for example.

In the above-described embodiment, the case where the composite material 1 is obtained by fluorine ion implantation has been described as an example. However, the method for manufacturing the composite material 1 is not limited to this, and the composite material 1 is obtained. As long as other methods are available, other methods than fluorine ion implantation may be employed.

<Biological implant>
Next, the biological implant which concerns on one Embodiment is demonstrated in detail using drawing. In this embodiment, a dental implant will be described as an example of a biological implant.

FIG. 2 is a schematic view showing the appearance of a dental implant according to an embodiment.

The dental implant 100 includes a fixture 101, an abutment 102 attached to the end of the fixture 101, and an artificial tooth 103 attached to the fixture 101 via the abutment 102.

In the dental implant 100, each of the fixture 101, the abutment 102, and the artificial tooth 103 includes the composite material 1. As described above, since the composite material 1 has antibacterial properties and a large hardness, the dental implant 100 can suppress bacterial growth, such as brushing, repeated use, or cleaning. It is possible to exhibit excellent durability against.

Here, each of the fixture 101, the abutment 102, and the artificial tooth 103 may be composed of only the composite material 1. These may be partially composed of the composite material 1 and the remaining portion may be composed of a material other than the composite material 1. Further, at least one of the fixture 101, the abutment 102, and the artificial tooth 103 may include the composite material 1, and the other member may include a material other than the composite material 1. According to the above configuration, the growth of bacteria on the implant surface is suppressed. For example, since the fixture 101 and the abutment 102 are used in an oxygen-deficient environment, it can be expected to suppress the growth of anaerobic bacteria. Further, for example, since the artificial tooth 103 is exposed in the oral cavity and exposed to air, growth of facultative anaerobic bacteria and aerobic bacteria can be expected. Therefore, the composite material 1 may be appropriately used for the fixture 101, the abutment 102, and the artificial tooth 103 according to the bacterial species whose growth is to be suppressed and the necessary antibacterial performance.

1st area | region 12 in the composite material 1 should just be located in the site | part which bacteria may contact in the dental implant 100, the site | part which may be worn out, etc., for example. For example, the dental implant 100 may be configured such that the first region 12 is located on the surfaces of the fixture 101, the abutment 102, and the artificial tooth 103. Further, for example, the dental implant 100 may be configured such that the first region 12 is positioned at each joint location of the fixture 101, the abutment 102, and the artificial tooth 103. This also applies to other members other than the living body implant and the living body implant described later.

As mentioned above, although one embodiment concerning this indication was illustrated, this indication is not limited to the embodiment mentioned above, and it cannot be overemphasized that it may be arbitrary, unless it deviates from the gist of this indication. .

For example, in the above-described embodiment, the case where the biological implant is a dental implant has been described as an example, but the biological implant is not limited thereto. For example, the living body implant may be an implant made of a living body metal such as titanium. Other biological implants include, for example, artificial joints such as femoral stems or acetabular shells, and spinal surgical implants such as spinal fusion instrumentation.

In the above-described embodiment, the case where the composite material 1 is used for a biological implant has been described as an example. However, the composite material 1 is not limited to use for a biological implant. That is, the composite material 1 may be used as a material for members that require antibacterial properties and high hardness. Other members include, for example, orthodontic wires, surgical instruments, injection needles, glasses frames, dishes, food factory lines, water bottle taps, kitchen knives, toilets, Washlets (registered trademark), faucets or water and sewage pipes Etc.

Hereinafter, the present disclosure will be described in detail with reference to examples. Note that the present disclosure is not limited to the following examples.

[Example 1 and Example 2]
<Production of composite material>
First, the following test pieces were prepared.
Test piece: C.I. P. Pure titanium with a thickness of 1 mm made of two types of titanium

The test piece described above was formed into a disk shape having a diameter of 14 mm and a thickness of 1 mm, and then ultrasonically washed with ethanol and acetone, and vacuum dried in a desiccator. And the fluorine ion was inject | poured on the surface of a test piece on different conditions, and the composite material 1 of Example 1 and Example 2 was obtained.

Fluorine ion implantation conditions are as follows.
Example 1
Injection energy: 40 keV
Implantation dose: 5 × 10 ¹⁷ atoms / cm ²
(Example 2)
Injection energy: 40 keV
Implantation dose: 5 × 10 ¹⁶ atoms / cm ²

The obtained composite material 1 was ultrasonically washed with ethanol and acetone, vacuum-dried in a desiccator, and then used for evaluation.

[Comparative Example 1]
Comparative Example 1 was the same test piece as in Example 1 and Example 2 in which fluorine ions were not implanted.

<Evaluation>
For the composite material 1 of Example 1 and Example 2, the fluorine concentration, hardness and crystal structure were measured. Moreover, about the composite material 1 of Example 1, antibacterial property was measured. For Comparative Example 1, hardness and antibacterial properties were measured.

FIG. 3 is a graph showing the measurement results of fluorine concentration in Example 1 and Example 2.

(Fluorine concentration)
The fluorine concentrations of Example 1 and Example 2 were measured by XPS and SIMS. Specifically, the fluorine concentration was determined by XPS in a region where the fluorine concentration was relatively large and exceeded the SIMS measurement range, and the fluorine concentration was determined by SIMS in other regions. Specifically, the fluorine concentration was determined by SIMS in the range where the fluorine concentration was up to 10 atomic%. Moreover, the fluorine concentration was calculated | required by XPS in the range whose fluorine concentration is 10 atomic% or more. Here, the XPS measurement was performed at a depth of 0 to 200 nm, and the SIMS measurement was performed at a depth of 0 to 900 nm. FIG. 3 shows only the measurement results at a depth of 0 to 200 nm. In FIG. 3, the depth of 0 nm indicates the surface 11 of the composite material 1. This also applies to FIG. 4 described later. The measurement conditions for XPS and SIMS are as follows.

(XPS measurement conditions)
Analyzer: X-ray photoelectron spectrometer “PHI Quantera II” manufactured by ULVAC-PHI
X-ray source: Monochrome AlKα
Sputtering ion: Ar ⁺
Acceleration voltage: 4 kV

(SIMS measurement conditions)
Analyzer: Secondary ion mass spectrometer “D-SIMS 6650” manufactured by ULVAC-PHI
Primary ion species: Cs ⁺
Secondary ion polarity: Negative
Acceleration voltage: 2 kV
Beam current: 25 nA
Charge compensation: None Raster size: 400 μm

From the measurement results, it was revealed that in Example 1, the maximum value of the fluorine concentration is located at a depth of 90 nm. The maximum fluorine concentration of Example 1 was 63 atomic%. In Example 2, it was revealed that the maximum value of the fluorine concentration is located at a depth of 46 nm. The maximum value of the fluorine concentration in Example 2 was 11 atomic%.

From the depth of 0 nm (surface 11) to the depth at which the fluorine concentration becomes 1 ppm was defined as the first region 12, and the thickness T was measured. The measurement results are as follows.
(Thickness T of the first region)
Example 1: 740 nm
Example 2: 390 nm

FIG. 4 is a graph showing the measurement results of hardness in Example 1, Example 2, and Comparative Example 1.

(hardness)
Hardness was measured by a nanoindentation method (ISO 14577 compliant). Here, the measurement was performed at a depth of 0 to 1000 nm. FIG. 4 shows only the measurement results at a depth of 0 to 500 nm.

The measurement conditions of hardness are as follows.
Measuring device: “Nanoindenter XP” manufactured by MTS Systems
Measurement mode: Continuous stiffness measurement Indentation depth: 1000 nm maximum
Hardness unit: Vickers hardness

From the measurement results, it was revealed that in Example 1, the maximum hardness value is located at a depth of 70 nm. The maximum hardness value of Example 1 was 5 GPa. In Example 2, it became clear that the maximum value of hardness is located at a depth of 20 nm. The maximum hardness value of Example 2 was 7 GPa.

(Crystal structure)
The crystal structure was evaluated by TEM, XRD and XPS. In each measurement of TEM, XRD, and XPS, the first region 12 is determined from the thickness T of the first region 12 described above, and the region located inward of the first region 12 is defined as the second region. .

The measurement conditions of TEM are as follows.
Analyzer: Transmission electron microscope “Talos F200X” manufactured by FEI
Accelerating voltage: 200kV
Beam current value: 150 pA
Measurement location: cross section of composite material 1 cut in thickness direction

The measurement conditions of XRD are as follows.
Analyzer: “X 'Pert PRO-MRD” manufactured by PANalytical
Tube: CuKα
Incident angle: 0.5 °
Measurement range: 10 to 120 °

XPS measurement conditions are the same as the fluorine concentration described above.

First, cross-sectional observation by TEM was performed. For the diffraction pattern, a database provided by the International Center for Diffraction Data (ICDD) was referred to (TiOF2: ICDD No. 00-008-0060, titanium α phase: ICDD No. 00-044-1294). As a result of observation, in both Example 1 and Example 2, a diffraction pattern attributed to TiOF ₂ (crystalline phase 2) was obtained in the first region 12, and a diffraction pattern of the titanium α phase (first in the second region). Two phases 32) were obtained.

In both Example 1 and Example 2, the first phase 31 was confirmed in the first region 12. In Example 1, the crystal phase 2 was confirmed more than the first phase 31. In Example 2, the first phase 31 was confirmed more than the crystal phase 2. In Example 1, the amorphous phase 4 and the mixed phase 5 were confirmed in the first region 12.

Next, measurement by XRD was performed. The diffraction pattern referred to JCPDS provided by ICDD. As a result of the measurement, a crystal structure different from the second region in the first region 12 was confirmed.

And the measurement by XPS was implemented. The assignment of peaks is shown in Table 1. As a result of measurement, in both Example 1 and Example 2, peaks attributable to TiF ₃ , TiF ₄ and F—TiO ₂ were obtained. Further, in Example 1, a peak attributed to the Ti—F—Ti bond was obtained, but this peak is considered to be attributable to titanium fluoride crystals. Otherwise, the state shown in FIG. 1 was confirmed.

(Antibacterial)
Antibacterial properties were measured by a film adhesion test using staphylococcus aureus (according to JIS Z 2801).

The measurement results are as follows.
Adherent viable count (CFUs)
Example 1: <10 (below detection limit)
Comparative Example 1: 17667

As a result of measurement, in Example 1, the number of viable bacteria was below the detection limit. Moreover, the antibacterial activity value of Example 1 was 3.2. Therefore, it was revealed that Example 1 has an antibacterial effect.

DESCRIPTION OF SYMBOLS 1 ... Composite material 2 ... Crystalline phase of titanium fluoride 3 ... Metal crystal phase of titanium 31 ... First phase 32 ... Second phase 4 ... Amorphous phase 5 ... Mixed phase 11 ... surface 12 ... first region 12a ... central portion T ... thickness A ... thickness direction 13 ... second region 100 ... dental implant 101 ... fixture 102 ... Abutment 103 ... Artificial tooth

Claims

Having a crystal phase of titanium fluoride and a metal crystal phase of titanium,
The titanium fluoride crystal phase is a composite material present in a first region located away from the surface in the depth direction.
The composite material according to claim 1, wherein the titanium fluoride is TiOF 2 .
The composite material according to claim 1 or 2, wherein the metal crystal phase has a first phase containing fluorine.
The composite material according to claim 3, wherein the first phase is located in the first region.
The metal crystal phase further includes a second phase located inward of the first phase;
The composite material according to claim 3 or 4, wherein the second phase does not contain fluorine.
The composite material according to claim 5, wherein the second phase is located inward of the first region.
The composite material according to any one of claims 1 to 6, further comprising an amorphous phase containing titanium and fluorine.
The composite material according to claim 7, further comprising a mixed phase of the amorphous phase, the crystal phase of the titanium fluoride, and the metal crystal phase.
9. The composite material according to claim 1, wherein the fluorine concentration shows a maximum value inward from the surface.
The composite material according to claim 9, wherein the fluorine concentration increases from the surface inward and reaches a maximum value.
The composite material according to claim 9 or 10, wherein the fluorine concentration reaches a maximum value in the first region.
The composite material according to claim 11, wherein the fluorine concentration reaches a maximum value on the surface side with respect to a central portion in the depth direction of the first region.
The composite material according to any one of claims 1 to 12, wherein the hardness shows a maximum value inward from the surface.
The composite material according to claim 13, wherein the hardness increases from the surface inward and reaches a maximum value.
The composite material according to claim 13 or 14, wherein the hardness reaches a maximum value in the first region.
The composite material according to claim 15, wherein the hardness reaches a maximum value on the surface side with respect to a central portion in a depth direction of the first region.
The composite material according to any one of claims 1 to 16, wherein the hardness shows a maximum value on the surface side from a position where the fluorine concentration shows a maximum value.
The composite material according to any one of claims 1 to 17, which is used for biological implants.
A biological implant comprising the composite material according to any one of claims 1 to 18.